First of all, I just wanna say nice post [@deia876lat]. Always good to see some HEMA in action, but there's just one thing. You mentioned Arn starting the match without [@Omni5876] writing that in their own post yet, so Omni, does deia have your permission to do that?

As for the insignia thing, I suppose if the non-standard equipment and the emblems on their armour aren't enough, we could say that all knights wear a crest in the shape of a shield somewhere on them, each symbol unique to the wearer and based on their knightly name. For example, Leo could have a white spider on a solid black background for his crest. Tyrhallan could have something like that, which he apparently already does. A swallow tailed kite. 

Knights don't really have a rank structure since all of them would be equals except for their Knight Captain, which is more of a title than a rank. Similar to how everyone just knows Barristan Selmy is the Lord Commander of the Kingsguard in Game of Thrones, so would it be assumed that everyone knows Tyrhallan is the leader of the knights. If knights did have an official rank structure though, it'd go something like: Knight apprentice (squire) > Knight > Senior Knight > Knight Captain.

As for the regular soldiers... I'll have to think about that.